Most volcanoes form at the boundaries of Earth's tectonic plates, which are huge slabs of crust and upper mantle that fit together like puzzle pieces. Think of these plates as massive rafts floating ...

Volcanoes are grouped into four types: cinder cones, composite volcanoes, shield volcanoes and lava volcanoes. Cinder cones are circular or oval cones made up of small fragments of lava from a single ...

Volcanoes can look like small mountains or hills. A volcano is an opening in the Earth's crust that allows magma, hot ash and gases to escape. Composite volcanoes are the most common type of volcano.